The way she professes to know things that she doesn't and the way that she is two-faced, shows her stupidity. Stupidity is defined by her lack of character. As he says, he doesn't judge her on superficial things that don't matter. I do agree that the song targets a certain type of woman -- it's not a misogynistic song. In a broader sense however -- and probably most importantly -- the "girl" is a metaphor for established society's closed-mindedness - devoid of trueness.
The way she professes to know things that she doesn't and the way that she is two-faced, shows her stupidity. Stupidity is defined by her lack of character. As he says, he doesn't judge her on superficial things that don't matter. I do agree that the song targets a certain type of woman -- it's not a misogynistic song. In a broader sense however -- and probably most importantly -- the "girl" is a metaphor for established society's closed-mindedness - devoid of trueness.